| Physella acuta | |
|---|---|
| Physella acuta | |
| Conservation status | |
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NE[1]
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| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| (unranked): | clade Heterobranchia clade Euthyneura clade Panpulmonata clade Hygrophila |
| Superfamily: | Planorboidea |
| Family: | Physidae |
| Subfamily: | Physinae |
| Tribe: | Physellini |
| Genus: | Physella |
| Species: | P. acuta |
| Binomial name | |
| Physella acuta (Draparnaud, 1805)[2] |
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| Synonyms | |
|
Physa acuta Draparnaud, 1805 |
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Physella acuta, common name the European physa, is a species of small, left-handed or sinistral, air-breathing freshwater snail, an aquatic gastropod mollusk in the family Physidae.
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Snails in the family Physidae have shells that are sinistral, which means that if the shell is held with the aperture facing the observer and the spire pointing up, then the aperture is on the left-hand side.
The shells of Physella species have a long and large aperture, a pointed spire, and no operculum. The shells are thin and corneous and rather transparent.
It was thought that indigenous distribution of Physella acuta is Mediterranean.[4][5] But if Physella heterostropha is a synonym, then as its indigenous distribution is considered as North-American.[6]
Physella acuta is the common species, which has invaded practically all fresh waters of the world, and is common in all of North America and Europe. The species seems to have first spread through Mediterranean regions and then more slowly into northern Europe.[3][6]
The distribution also includes Mediterranean regions and Africa.[10]
The distribution includes the United States: Maryland, New Jersey, and Virginia. The initial introduction in the United States was probably from aquarium release, aka "aquarium dumping".[10]
This species lives in freshwater rivers, streams, lakes, ponds, and swamps.[10]
Physella acuta is frequently found in anthropogenic reservoirs, occurring in warm water discharges from power stations and in some rivers, but very rarely and not numerously in clay pit ponds. It can survive well under temporary harsh conditions (extreme temperature and water pollution), as long as they are short-lived.[6]
These snails eat dead plant and animal matter and various other detritus.
While Physella acuta forages mainly on epiphytic vegetation and on the macrophytes, other gastropods (Planorbis planorbis, Radix ovata) exploit the algal cover or phytobentos on the bottom. Therefore competition between Physella acuta and other gastropods appears to be minimal.[6]
This species successfully co-exists with other alien gastropods: for example with Potamopyrgus antipodarum in many streams, lakes and ponds in New Zealand and with Lithoglyphus naticoides in the Danube River.[6]
This article incorporates CC-BY-2.0 text (but not under GFDL) from reference.[6]